Fuse plug



Dec. 18 1923. 1,477,643

J. B. GLOWACKI I FUSE `PLUG Filed July 21 1919 lllllllllfll! lilium@ IlIsl.' "l' f 225; 1 inw EDF@ HMM/c Jb/m25'. @mmc/fa Patented Dec. 18,1923.

UNITED STATES JOHN B. GLOWACKI, OF CHICAGO, ILLINOIS.

FUSE PLUG.

Application tiled July 21.

/'o all. 'whom it may concern.:

Be it known that I, JOHN B. Gnowacxl,

a subject of the Republic of Poland, having declared my intention tobecome a citizen of the United States, and a resident of the city ofChicago, in 'the county of Cook and State of Illinois, have inventedcertain new and useful Im rovements in a Fuse Plug; and I do here ydeclare that the following is a full, clear, and exact description ofthe same, reference being had to the ac3 companying drawings, and to thenumerals of reference marked thereon, which form a part of thisspecification.

This invention relates to screw contact fuse plugs, moreparticularlyplugs adapted to screw into a fuse cutout box.

Hitherto screw contact fuse plu have been constructed so that it is dicult to insert a new fuse link after the fuse has' blown and further inmany cases insufficient ventilation has beenv provided around the fuselink to ensure its action at proper times and prevent fusion thereof asthe result of long continued passage of current of safe am ierage.

ne of the objects, therefore, of this inrention is to provide a simple,economical form of construction of screw contact fuse plugs in which thefuse is firmly held and yet readily replaceable when necessary.

Another ob]ect of the invention is to provide means for allowin air topass completely around the fuse l1nk.

A further object of the invention is to provide an im roved form of fuselink.

Other and urther important objects ot this invention will be apparentfrom the diS- closures in the specification and drawings.

The invention (in a preferred form) is illustrated in the drawings andhereinafte more fully described.

()n the drawings Figure 1 is a side elevation of a fuse plug embodyingthe features of t-he present 1nvention.

Figure 2 is a section on the line 2-2 of Figure 1.

Figure 3 is a plan view of the lug. Figure 4 is a section on the ine4--4 of igure 5 is an axial section through the fuse carrier` with partsin elevation.

Figure 6 is a section on the line` 6-6 of Figure 4, and

ltl

1919. Serial No. 312,341.

the cup may be provided to prevent detachment of the insulation 2 fromthe cup 1. Centrally and detachably arranged within the cup 1, is a fusecarrier 5 comprising aI central cylindrical portion 6 of insulatingmaterial and metallic end pieces 7 and 8 screwed or cast into' each end.For, conneet-ing this carrier 5 to the cup 1 the end piece 7 may beprovided with an extension 18 of reduced size adapted to fitsnuglywithin a cylindrical recess 9 in the end of the cup. The outer endpiece is conveniently dished at its end, as at 15, forbetter engagementwith the central contact o f a socket.

A fuse 11 may be detachably secured to one side of the carrier 5 by anysuitable means such as split rings 10, which clam the ends of the stripto the two metallic end pieces 7 and 8.

Preferably movement of these rings towards the center of the carrier islimited by providing longitudinal ribs 12 on the central insulatingportion 6 of the carrier.

Although various forms of fuse strip may be. employed I prefer to use astrip having a series of portions 13 of reduced width as shown moreparticularly in Figure 2. The cross-section of theseportions 13determines the current strength at which the fuse will blow and byvprovidin a plurality of such sections arclng is avoi ed since one ormore of the intermediate parts of the fuse will fall when the sections13 above and below it fuse, thereby producing a much wider gap thanwould be produced by the fusing of a single section 13.

Preferably provision is'made for allowing free circulation of air allaround the parts 13 of the fuse strip and inthe form of constructionshown this is accomplished by forming a series of circumferentialgrooves 14 in the insulating part '6 of the carrier adapted to registerwith the parts 13 of the fuse strip,

.The operation is as follows:

The fuse carrier 5 is detached from the plug and the rings 10 slippedoff the ends. A fuse strip 11 is then laid along one side of the carrierwith its parts 13 registering with the grooves 14. The rings are nowslipped over the ends of the carrier to clamp the ends of the fuse linkto the end pieces 7 and 8.

Next the carrier is connected to the cup 1 by thrusting the extension 18into the recess 9 by which it is frictionally held.

rlhe plug is now ready to screw into the fuse cutout box.

ll am aware that numerous details of construction may be varied `througha wide range without departing from the principles of this invention andl therefore do not purpose limiting the patent granted further thannecessitated by the prior art and the annexed claims.

ll claim as my invention 1. A fuse comprising a cylinder having metallicend portions and an intermediate portion of insulating material andsplit metallic rings for detachably securing a strip of fusible materialalong one side of the cylinder with its ends in contact with themetallic end portions, said cylinder being provided with a longitudinalridge adapted to prevent displacement of the split metallic rings.

2. fuse plug comprising a threaded metallic shell, a cylinder arrangedconcentrioally within'the shell having metallic end portions and anintermediate circumferentially grooved portion of insulating material`one end portion being electrically connected germen with the shell andthe other being adapted for electrical connection with a contact 1n asocket, a strip offusible material havin a portion of reduced width andsplit meta lic rings for securing said strip along one side of thecylinder with its ends in contact with the metallic end portions and itsportion of reduced width in register with the groove in the cylinder. I

3. A fuse plug comprising a cylinder closed at one end, a cylinder ofinsulating material disposed therein@ a fuse carried on the outside ofthe second cylinder, said assembly forming an open air space between thecylinders.`

el. A fuse plug comprising a cylinder, closed at one end, anothercylinder of insulating' material frictionallyvheld therein, a fusecarried on the outside of the second cylinder, said assembly forming anopen ended air space between the cylinders.

5. ln a fuse plugq a. hollow cylinder of sheet metal closed at one endand open at the other, the side wall of said cylinder toward the openend being formed into a Eea

